I'm just speaking in science terms... that sounds a bit too philosophical for me.
Yeah, this is actually philosophy, not really science!
This is one of those things that's always busted my brain. If energy/matter cannot be created or destroyed, how'd it get here in the first place?
Please, anyone with a better understanding of QM than me (which is pretty much everyone on this forum), I'd love to know the answer to this. I've always seen it as sort of a physics paradox.
See #14 for one answer. Conservation of energy and matter is not actually an applicable principle of physics.
Another answer is that your question appears to assume that time is endless both into the future and into the past. But that assumption is unfounded.
So this forum is not the right place to discuss it.
By spacetime having a geometry in which timelike curves have a finite extent into the past. Currently physicists don't know for sure whether that feature of idealized models based on GR actually applies to our universe; but the models themselves are perfectly consistent, and answer the question you pose here.
This, as you say, is an assumption. But it is not a necessary assumption, as there are consistent models in which it does not hold. See above.
The OP question has been sufficiently addressed. Thread closed.
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